(中南大學(xué) 化學(xué)化工學(xué)院，長沙 410083)
摘 要: 研究L-白氨酸對鋁酸鈉溶液種分分解率及其產(chǎn)物Al(OH)3粒度和形貌的影響，并結(jié)合表面張力和27Al NMR檢測手段探討L-白氨酸對鋁酸鈉溶液種分過程影響的作用機(jī)制。結(jié)果表明：在所選實(shí)驗(yàn)條件下，L-白氨酸可以強(qiáng)化分解過程，并在低濃度下可使種分產(chǎn)品細(xì)化；L-白氨酸的加入可以降低溶液的表面張力，27Al NMR特征峰峰形和化學(xué)位移均無顯著改變，但半峰寬縮小；結(jié)合種分實(shí)驗(yàn)，認(rèn)為添加劑主要是通過吸附在晶種表面，降低了氫氧化鋁結(jié)晶活化能，促進(jìn)氫氧化鋁的快速析出。
關(guān)鍵字: L-白氨酸；鋁酸鈉溶液；晶種分解；分解率
sodium aluminate solution
（School of Chemmistry and Chemical engineering ,Central South University, Changsha 410083, China）
Abstract:The effects of L-leucine on the seeded precipitation rate of sodium aluminate solution, the particle size and morphology of the products were studied. The surface tension and 27Al NMR were used in order to investigate the interaction mechanism of L-leucine on the seeded precipitation. The results indicate that L-leucine can promote the precipitation at low concentration and the product becomes finer. The surface tension of sodium aluminate solution decreases with the addition of L-leucine. According to the 27Al NMR spectra, the peak profile and chemical shift of the characteristic peak have no obvious change compared with the blank solution, however, the half-peak width reduces. From the results of seed agglomeration, it can be inferred that the precipitation of Al(OH)3 is promoted by the adsorption of additive molecules on the surface of seed particles, thus the crystallization activation energy decreases.
Key words: L-leucine; sodium aluminate solution; seeded precipitation; precipitation rate
